TESTING/LIN/sgbt02.f(3)    Library Functions Manual    TESTING/LIN/sgbt02.f(3)

NAME
       TESTING/LIN/sgbt02.f

SYNOPSIS
   Functions/Subroutines
       subroutine sgbt02 (trans, m, n, kl, ku, nrhs, a, lda, x, ldx, b, ldb,
           rwork, resid)
           SGBT02

Function/Subroutine Documentation
   subroutine sgbt02 (character trans, integer m, integer n, integer kl,
       integer ku, integer nrhs, real, dimension( lda, * ) a, integer lda,
       real, dimension( ldx, * ) x, integer ldx, real, dimension( ldb, * ) b,
       integer ldb, real, dimension( * ) rwork, real resid)
       SGBT02

       Purpose:


            SGBT02 computes the residual for a solution of a banded system of
            equations op(A)*X = B:
               RESID = norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ),
            where op(A) = A or A**T, depending on TRANS, and EPS is the
            machine epsilon.
            The norm used is the 1-norm.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                     Specifies the form of the system of equations:
                     = 'N':  A    * X = B  (No transpose)
                     = 'T':  A**T * X = B  (Transpose)
                     = 'C':  A**H * X = B  (Conjugate transpose = Transpose)

           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           KL

                     KL is INTEGER
                     The number of subdiagonals within the band of A.  KL >= 0.

           KU

                     KU is INTEGER
                     The number of superdiagonals within the band of A.  KU >= 0.

           NRHS

                     NRHS is INTEGER
                     The number of columns of B.  NRHS >= 0.

           A

                     A is REAL array, dimension (LDA,N)
                     The original matrix A in band storage, stored in rows 1 to
                     KL+KU+1.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,KL+KU+1).

           X

                     X is REAL array, dimension (LDX,NRHS)
                     The computed solution vectors for the system of linear
                     equations.

           LDX

                     LDX is INTEGER
                     The leading dimension of the array X.  If TRANS = 'N',
                     LDX >= max(1,N); if TRANS = 'T' or 'C', LDX >= max(1,M).

           B

                     B is REAL array, dimension (LDB,NRHS)
                     On entry, the right hand side vectors for the system of
                     linear equations.
                     On exit, B is overwritten with the difference B - A*X.

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  IF TRANS = 'N',
                     LDB >= max(1,M); if TRANS = 'T' or 'C', LDB >= max(1,N).

           RWORK

                     RWORK is REAL array, dimension (MAX(1,LRWORK)),
                     where LRWORK >= M when TRANS = 'T' or 'C'; otherwise, RWORK
                     is not referenced.

           RESID

                     RESID is REAL
                     The maximum over the number of right hand sides of
                     norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 147 of file sgbt02.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/LIN/sgbt02.f(3)